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   https://doi.org/10.1016/j.ijmachtools.2021.103797  

   Li, Xuxiao ; Guo, Qilin ; Chen, Lianyi ; Tan, Wenda ( November 2021 , International Journal of Machine Tools and Manufacture)

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2. Difference between powder bed density and green density for a free-flowing powder in binder jetting additive manufacturing

   https://doi.org/10.1016/j.jmapro.2022.10.030  

   Li, Ming ; Miao, Guanxiong ; Du, Wenchao ; Pei, Zhijian ; Ma, Chao ( December 2022 , Journal of Manufacturing Processes)
3. Vapor-induced flow and its impact on powder entrainment in laser powder bed fusion

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4. Microstructure and corrosion behavior of differently heat-treated Ti-6Al-4V alloy processed by laser powder bed fusion of hydride-dehydride powder

   https://doi.org/10.1016/j.corsci.2023.111495  

   Delpazir, Melody H. ; Asherloo, Mohammadreza ; Nasiri Khalil Abad, Sajjad ; Thompson, Alaina ; Guma, Victor ; Bagi, Sourabh D. ; Sreenivas, Keerthi Kumar ; Paliwal, Muktesh ; Terry, Jeff ; Rollett, Anthony D. ; et al ( November 2023 , Corrosion Science)

   This study investigates the use of hydride-dehydride non-spherical Ti-6Al-4V powders in laser powder bed fusion process and the effects of post-heat-treatments on additively manufactured parts. As-built parts show anisotropic microstructure with α′ martensite and some β phases. Post heat-treated parts exhibit α + β phases, with characteristics dependent on the heat treatment. Heat treatment below β-transus leads to homogenized grain structures with improved corrosion resistance. Electrochemical analysis reveals a very stable corrosion rate due to faster formation of a protective passive layer aided by the fine-structured β phase. X-ray photoelectron spectroscopy examines corrosion behavior and film growth mechanism in saline water. 

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5. Discrete-Element Simulation of Powder Spreading Process in Binder Jetting, and the Effects of Powder Size

   https://doi.org/10.1115/MSEC2021-63351  

   Clares, Ana Paula ; Manogharan, Guha ( June 2021 , Discrete-Element Simulation of Powder Spreading Process in Binder Jetting, and the Effects of Powder Size)

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   Binder Jetting has gained particular interest amongst Additive Manufacturing (AM) techniques because of its wide range of applications, broader feasible material systems, and absence of rapid melting-solidification issues present in other AM processes. Understanding and optimizing printing parameters during the powder spreading process is essential to improve the quality of the final part. In this study, a Discrete Element Method (DEM) simulation is employed to evaluate the powder packing density, flowability, and porosity during powder spreading process utilizing three different powder groups. Two groups are formed with monoidal size distributions (75–84 μm and 100–109 μm), and the third one consisting of a bimodal distribution (50 μm + 100 μm).

   A thorough investigation into the effects of powder size distribution during the powder spreading step in a binder jetting process is conducted using ceramic foundry sand. It was observed that coarser particles result in higher flowability (62% decrease in repose angle) than finer ones due to the cohesion effect present in the latter. A bimodal size distribution yields the highest packing density (8% increase) and lowest porosity (∼12% reduction) in the powder bed, as the finer particles fill in the voids created between the coarser ones. Findings from this study are directly applicable to binder-jetting AM process, and also offer new insights for AM powder manufacturers.

    

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